Columbia University has been an active contributor to the MFMU since 2001 and is now submitting a competitive renewal. They presently are ranked fourth overall in participation and have routinely recruited in the top half of all centers. Since the last application, the Division has grown to 17 MFM specialists, 10 of which are available to the network; all of whom have protected research time. The faculty have extensive experience in multicentered collaborative research; including protocol design and analysis. Ronald Wapner, MD has been recruited to be the PI of this application. He was previously PI at both Drexel and Thomas Jefferson University. Under his direction these sites routinely ranked among the top 5 centers. Drexel is presently ranked second. A concept evaluating the relationship of maternal genotype to preterm birth has been developed and demonstrates the center's capabilities at protocol development and their understanding of the value of a large collaborative network. This trial specifically evaluates variations in the (32adrenergicreceptor and the impact on preterm birth and the response to tocolysis. Interactions between other genotypes suggested to increase preterm birth and specific demographic and environmental variables will be evaluated. olumbia has the research infrastructure to be successful as a participant in the MFMU which includes experienced research nurses, a perinatal database, and a delivery service of over 6000 deliveries/yr in a single institution. Additional resources available include perinatal epidemiology, basic science expertise, and :ormal relationships with community hospitals providing access to additional patients if and when necessary.